血管紧张素Ⅱ促心肌细胞蛋白质合成中信息传递途径的研究

体外研究表明：血管紧张素Ⅱ（ＡｎｇⅡ）可引起心肌细胞肥大，但其信息传递途径尚不清楚。本文通过＾３Ｈ－Ｌｅｕ掺入率的测定与ＲＮＡ狭线杂交技术，初步探讨了ＡｎｇⅡ受体、Ｃａ＾２＋及蛋白激酶Ｃ（ＰＫＣ）在ＡｕｇⅡ刺激乳鼠心肌细胞蛋白质合成中的作用，并观察了ＡｎｇⅡ对原癌基因ｃ－ｆｏｓ表达的影响。结果发现，培养液中加入钙通道阻断剂－Ｖｅｒａｐａｍｉｌ、细胞外钙螯合剂－ＥＧＴＡ、肌浆网钙释放抑制剂－Ｄａｎｔ     

肾上腺髓质素抑制内皮素1,血管紧张素Ⅱ刺激的肺动脉平滑？…

目的：研究肾上腺髓素（ＡＭ）对内皮素１（ＥＴ－１）、血管紧张素Ⅱ（ＡｎｇⅡ）促肺动脉平滑肌细胞增殖的影响。方法：体外增减兔肺动脉平滑肌细胞,采用＾３Ｈ－ＴｄＲ掺入法观察不同剂量ＡＭ对ＥＴ－１,ＡｎｇⅡ促肺动脉平滑肌细胞蛋白质合成的影响。结果：１×１０＾－９ｍｏｌ／Ｌ的ＥＴ－１,１×１０＾－８ｍｏｌ／Ｌ的ＡｎｇⅡ明显增加培养的平滑肌细胞＾３Ｈ－ＴｄＲ掺入量。１×１０＾－７￣２×１０＾－８ｍｏｌ／Ｌ深     

血管紧张素Ⅱ对血管平滑肌细胞促增生作用的研究

目的：探讨血管紧张素Ⅱ（ＡｎｇⅡ）对血管平滑肌细胞的致增生效应及洛沙坦的拮抗作用。方法：采用贴块法培养幼兔主动脉平滑肌细胞,通过检测细胞甲基－＾３Ｈ胸腺嘧啶核苷（＾３Ｈ－ＴｄＲ）掺入、ＭＴＴ廓清和细胞数量赤评价不同浓度ＡｎｇⅡ及／或洛沙坦预自理对血管平滑肌细胞增生的影响。结果：ＡｎｇⅡ呈剂量依赖性地增加平滑肌细胞的＾３Ｈ－ＴｄＲ掺入和ＭＴＴ廓清而对血管平滑肌细胞数量无明显影响;洛沙坦预处理可显著地     

自发性高血压大鼠主动脉血管平滑肌细胞异常增殖和自身肾素－血管紧张素系统的关系

目的以２０周龄自发性高血压大鼠（ＳＨＲ）和正常血压大鼠（ＷＫＹ）胸主动脉平滑肌细胞（ＡＳＭＣ）为模型，探讨ＳＨＲＡＳＭＣ异常增殖和自身肾素－血管紧张素系统（ＲＡＳ）的关系。方法用３Ｈ－ＴｄＲ参入量和倍增时间（ＤＴ）反映ＡＳＭＣ的增殖能力，放射免疫法测定血管紧张素Ⅱ（ＡｎｇⅡ）浓度，紫外分光光度法测定血管紧张素转换酶（ＡＣＥ）活性。结果（１）ＳＨＲＡＳＭＣ３Ｈ－ＴｄＲ参入量显著高于ＷＫＹ，ＤＴ显著短于ＷＫＹ（Ｐ＜０．０１）。基础状态下，ＳＨＲＡＳＭＣ合成ＡｎｇⅡ、ＡＣＥ以及分泌ＡｎｇⅡ的量显著高于ＷＫＹ（Ｐ＜０．０１）。（２）在含２％ＦＣＳ的培养基中，１０－６ｍｏｌ／ＬＡｎｇⅡ使ＳＨＲ、ＷＫＹ的３Ｈ－ＴｄＲ参入量分别提高到对照组的３．３倍、２．２倍（Ｐ＜０．０１），ＳＨＲＡＳＭＣ在不同浓度ＡｎｇⅡ刺激时的３Ｈ－ＴｄＲ参入量显著高于ＷＫＹ（Ｐ＜０．０１），１０－６ｍｏｌ／ＬＡｎｇⅡ使ＳＨＲＡＳＭＣ细胞数增加７２．５±２３．１％（Ｐ＜０．０１），ＷＫＹＡＳＭＣ细胞数无显著增加，１０倍浓度ＡｎｇⅡ的Ｓａｒａｌａｓｉｎ对ＳＨＲ、ＷＫＹ３Ｈ－ＴｄＲ参入的抑制率分别为６６．７±３．３％，４４．７±９．９％（Ｐ＜０．０１）     

血管紧张系Ⅱ受体基因敲除对跨膜钙内流的作用

目的 观察血管紧张素Ⅱ受体亚型（ＡＴ１ａ）基因敲除对跨膜钙内流的影响。方法 培养ＡＴ１ａ基因敲除及其野生型对照小鼠的主动脉血管平滑肌细胞（ＶＳＭＣ）和应用荧光倒置显微镜及钙荧光指示剂Ｆｕｒａ－２／ＡＭ动态观测ＶＳＭＣ钙离子（Ｃａ＾２＋）ｉ变化。结果 在血管紧张素Ⅱ（ＡｎｇⅡ）刺激下钙内流显著增加,ＡＴ１ａ敲除组ＶＳＭＣ钙净增值为（２０４±２２）ｎｍｏｌ／Ｌ,基础（Ｃａ＾２＋）ｉ为（１０８±９）ｎｍ     

一氧化氮,内皮素和血管紧张素对VSMC中Cdk2基因表达的调控

目的：研究细胞周期依赖性激酶２（Ｃｄｋ２）在ＮＯ、内皮素１（ＥＴ－１）及血管紧张素Ⅱ（Ａｎｇ Ⅱ）促血管平滑肌细胞（ＶＳＭＣ）增殖中的作用。方法：应用半定量ＲＴ－ＰＣＲ法测定样品Ｃｄｋ２水平；＾３Ｈ－ＴｄＲ参入方法测定细胞ＤＮＡ合成水平。     

血管紧张素Ⅱ对心肌梗塞后心肌细胞核酸,蛋白质合成…

通过分离、培养心肌梗塞后成年大鼠的心肌细胞（ＭＣ），观察了血管紧张素Ⅱ（ＡｎｇⅡ）在不同处理因素对照下，对ＭＣ核酸、蛋白质合成的影响。结果显示：在相同浓度的ＡｎｇⅡ（１０＾－７Ｍ）作用下，ＭＩ组ＭＣ的ＲＮＡ和蛋白质的合成速率均显著高于假手术组（ｐ〈０．０５）。 ＡｎｇⅡ的上述作用，可分别被ＡＴ１受体阻滞剂Ｌｏｓａｒｔａ ｎ、特异性ＡｎｇⅡ拮抗剂＾〔１，３〕ＡｎｇⅡ和血管紧张素抗肽（Ａｍｇ－ＡＰ）ＰＦ     

血管紧张素Ⅱ研究进展

肾素—血管紧张素系统（ＲＡＳ）完全涉及心血管功能的自身稳定性，其生理作用的主要调节剂是血管紧张素Ⅱ（ＡｎｇⅡ）。ＡｎｇⅡ的前体—血管紧张素肽原被特异的蛋白酶肾素水解，导致１０个氨基酸的ＡｎｇⅠ生成，另一种蛋白酶血管紧张素转换酶（ＡＣＥ）从ＡｎｇⅠ上水...     

Irbesartan对内皮剥脱后血管平滑肌细胞增生的影响

观察新的非肽类血管紧张素Ⅱ的１型受体拮抗剂对血管平滑肌细胞增生的影响。方法：大鼠髂动脉球囊内皮剥脱术后ＶＳＭＣ过度增生模型，采用＾３Ｈ－ＴｄＲ和＾３Ｈ－Ｌｅｕ掺入，。免疫组化染以检测ＶＳＭＣ中增殖细胞核抗遥表达及图象分析血管壁形态学变化的方法。     

血管紧张素Ⅱ受体拮抗剂研究进展

肾素－血管紧张素－醛固酮系统是调节血压的重要内分泌系统,在高血压病因学中占重要地位,肾素－血管紧张素系统（ＲＡＳ）产生的最终生理活性物质为血管紧张素Ⅱ（ａｎｇｉｏｔｅｎｓｉｎⅡ,ＡｎｇⅡ）。临床上普遍使用的降压药物血管紧张素转化酶（ＡＣＥ）抑制剂能很...     

Effects of cyclosporine A on angiotensin II-induced cardiomyocyte hypertrophy in neonatal rats

Summary The effects of cyclosporine A (CsA) on Angiontensin II (Ang II)-induced protein contents, c-fos protein levels and cytosolic Ca²⁺ level ([Ca²⁺]i) in cultured cardiomyocytes of neonatal rats were observed. Total protein contents were determined by Bradford method. The expression of c-fos protein was detected by Western blot. [Ca²⁺]i labeled with fluorescent probe Fluo-3/AM was measured under a laser scanning confocal microscope. The results revealed that as compared with control, the total protein contents were increased in cardiomyocytes treated with Ang II (10⁻⁷ mol/ L), which could be inhibited by CsA in a dose-dependent manner. It was found that Ang II could increase the c-fos protein expression, which could be inhibited by CsA in a dose-dependent manner. Ang II induced the [Ca²⁺]i elevation in cardiomyocytes. CsA did not influence the resting intracellular Ca²⁺, but inhibited significantly the Ang II-induced [Ca²⁺]i elevation. It was concluded that CsA can suppress the Ang II-induced c-fos protein expression and [Ca²⁺]i elevation in single cardiomyocyte, which might pay a role in the prevention of Ang II-induced cardiomyocyte hypertrophy by CsA. Han Zhaomin, female, born in 1974, Pharmacist     

Effects of Cyclosporine A on Angiotensin Ⅱ-induced Cardiomyocyte Hypertrophy in Neonatal Rats

The effects of cyclosporine A (CsA) on Angiontensin Ⅱ (Ang Ⅱ )-induced protein contents, c-fos protein levels and cytosolic Ca2+ level ([Ca2+ ]i) in cultured cardiomyocytes of neonatal rats were observed. Total protein contents were determined by Bradford method. The expression of c-fos protein was detected by Western blot. [Ca2+ ]i labeled with fluorescent probe Fluo-3/AM was measured under a laser scanning confocal microscope. The results revealed that as compared with control, the total protein contents were increased in cardiomyocytes treated with Ang Ⅱ (10-7 mol/L), which could be inhibited by CsA in a dose-dependent manner. It was found that Ang Ⅱ could increase the c-fos protein expression, which could be inhibited by CsA in a dose-dependent manner.Ang Ⅱ induced the [Ca2+ ]i elevation in cardiomyocytes. CsA did not influence the resting intracellular Ca2+ , but inhibited significantly the Ang Ⅱ-induced [Ca2+ ]i elevation. It was concluded that CsA can suppress the Ang Ⅱ-induced c-fos protein expression and [Ca2+ ]i elevation in single cardiomyocyte, which might play a role in the prevention of Ang Ⅱ -induced cardiomyocyte hypertrophy by CsA.     

丝裂素活化蛋白激酶参与AngII诱导心肌细胞血小板衍生生长因子受体的表达

目的　探讨丝裂素活化蛋白激酶在血管紧张素II(AngII)诱导心肌细胞血小板衍生生长因子受体 - β(PDGF - β)表达中的作用。 方法　分离纯化培养的乳鼠心肌细胞 ,以10 -7mol·L-1AngII刺激为AngII组 ;以 10 -5mol·L-1PD980 5 9(一种丝裂素活化蛋白激酶抑制剂 )预孵育 30min10 -7后再用AngII刺激为PD980 5 9组 ,以正常的乳鼠心肌细胞为对照组 ;免疫印迹法测定培养 2 4h时心肌细胞PDGF - β受体的含量。 结果　AngII刺激培养 2 4h的乳鼠心肌细胞PDGF - β受体表达增强 (P <0 .0 5 ) ,PD980 5 9可部分抑制AngII对PDGF - β受体表达的诱导作用。结论　丝裂素活化蛋白激酶参与AngII上调心肌细胞PDGF - β受体表达的信号转导途径     

PP60c-Src在血管紧张素Ⅱ对大鼠血管平滑肌细胞信息转导中的作用

目的：通过观察c—Src在AngⅡ对大鼠血管平滑肌细胞(VSMC)丝裂原活化的蛋白激酶(MAPK)活性和c—fos蛋白表达的影响，以进一步了解AngⅡ促VSMC增殖的细胞内信息转导机制。方法：原代和传代培养SD大民主动脉VSMC，以脂质体包裹反义c—Src寡脱氧核夺酸(Oligodeoxynucleotides ODNs)转染培养的VSMC以抑制c—Src蛋白表达和激酶活性。以未转染的VSMC为对照，观察10^7mol/L AngⅡ刺激对转染的VSMC的MAPK活性和c—fos蛋白表达的影响。蛋白免疫沉淀和酶自身磷酸化率测定c—Src激酶活性；髓鞘碱性蛋白(MBP)底物磷酸化率测定MAPK放酶活性；Western blot免疫印迹法测定c—Src和c—fos蛋白表达情况。始果：转染不同浓度反义c—Src()DNs的VSMCc—Src蛋白含量至浓度依赖性降低，0.2μmol/L、0.5μmol/L、1．0μmol／L和2．0μmol/L分别为对照的68．2％、34．7％、30。3％和15．8％，经方差分析具有显著性意义(P＜0.01)。c—Src激酶活性也显著抑制；以AngⅡ刺激经转染反义c—Src DNs的VSMC，c—Src激酶活性增幅仅为对照组的8．7％；MAPK活性仅为对照的1．6％；c—fos蛋白表达的增幅为对照组的30．0％。结论：AngⅡ可诱导VSMC c—Src激活和细胞内信息转导，且AngⅡ引起的MAPK和c—fos的激活依赖于c—Src的激活，提示c—Src是AngⅡ促血管平滑细胞增殖的重要信息分于。     

Effect of Atorvastatin on Expression of Peroxisome Proliferator-activated Receptor Beta/delta in AngiotensinⅡ-induced Hypertrophic Myocardial CellsIn Vitro

Objective To explore the effect of atorvastatin on cardiac hypertrophy and to determine the potential mechanism involved. Methods Anin vitro cardiomyocyte hypertrophy from neonatal rats was induced with angiotensinⅡ (AngⅡ) stimulation. Before AngⅡ stimulation, the cultured rat cardiac myocytes were pretreated with atorvastatin at different concentrations (0.1, 1, and 10μmol/L). The following parameters were evaluated: the myocyte surface area,3H-leucine incorporation into myocytes, mRNA expressions of atrial natriuretic peptide, brain natriuretic peptide, matrix metalloproteinase 9, matrix metalloproteinase 2, and interleukin-1β, mRNA and protein expressions of theδ/β peroxisome proliferator-activated receptor (PPAR) subtypes. Results It was shown that atorvastatin could ameliorate AngⅡ-induced neonatal cardiomyocyte hypertrophy in the area of cardiomyocytes,3H-leucine incorporation, and the expression of atrial natriuretic peptide and brain natriuretic peptide markedly. Meanwhile, atorvastatin also inhibited the augmented mRNA level of several cytokines in hypertrophic myocytes. Furthermore, the down-regulated expression of PPAR-δ/β at both the mRNA and protein levels in hypertrophic myocytes could be significantly reversed by atorvastatin treatment. Conclusions Atorvastatin could improve AngⅡ-induced cardiac hypertrophy and inhibit the expression of cytokines. Such effect might be partly achieved through activation of the PPAR-δ/β pathway.     

血管紧张素Ⅱ2型受体基因缺失抑制诱导的成纤维细胞凋亡

目的探讨血管紧张素Ⅱ（ＡｎｇⅡ）２型受体（ＡＴ２）基因表达与成纤维细胞凋亡的关系。方法分别从正常（ＡＴ２＋／＋）和ＡＴ２受体基因缺失（ＡＴ２／）胎鼠培养皮肤成纤维细胞,经ＡｎｇⅡ诱导后,采用ＲＴＰＣＲ检测成纤维细胞ＡｎｇⅡ的ＡＴ１和ＡＴ２受体ｍＲＮＡ表达,分别用基因组ＤＮＡ电泳、ＴＵＮＥＬ染色和流式细胞仪等定性和定量方法检测细胞的凋亡改变。结果经１０８、１０７、１０６和１０５ｍｏｌ／Ｌ浓度的ＡｎｇⅡ刺激４８小时,成纤维细胞的ＡＴ１和ＡＴ２受体基因表达均有显著增强,并与浓度呈正相关。经１０６和１０５ｍｏｌ／Ｌ浓度的ＡｎｇⅡ诱导７２小时,ＡＴ２＋／＋成纤维细胞出现了明显的标志着细胞凋亡的基因组ＤＮＡ片段化,凋亡细胞分别是（１２３±２７）％和（２１７±６７）％,而ＡＴ２／成纤维细胞则未出现明显的细胞凋亡改变。结论ＡＴ２受体基因缺失后,抑制了ＡｎｇⅡ介导的成纤维细胞凋亡,为进一步揭示ＡｎｇⅡ的生理和病理作用提供了实验依据     

Altered expression of renal bumetanide-sensitive sodium-pota-ssium-2 chloride cotransporter and Cl- channel -K2 gene in angiotensin Ⅱ-infused hypertensive rats

Background Little information is available regarding the effect of angiotensin Ⅱ (Ang Ⅱ) on the bumetanide-sensitive sodium-potassium-2 chloride cotransporter (NKCC2), the thiazide-sensitive sodium-chloride cotransporter (NCC), and the Cl- channel (CLC)-K2 at both mRNA and protein expression level in Ang Ⅱ-induced hypertensive rats. This study was conducted to investigate the influence of Ang Ⅱ with chronic subpressor infusion on nephron-specific gene expression of NKCC2, NCC and CLC-K2.Methods Sprague Dawleys rats were treated subcutaneously with either Ang Ⅱ (100 ng·kg-1·min-1 ) or vehicle for 14 days. Expression of NKCC2, NCC and CLC-K2 mRNA in kidneys was determined by real time polymerase chain reaction (PCR). Western blotting analysis was used to measure NKCC2 and NCC protein expression. Results Ang Ⅱ significantly increased blood pressure and up-regulated NKCC2 mRNA and protein expression in the kidney. Expression of CLC-K2 mRNA in the kidney increased 1.6 fold (P&lt;0.05).There were no changes in NCC mRNA or protein expression in AngII-treated rats versus control.Conclusions Chronic subpressor Ang Ⅱ infusion can significantly alter NKCC2 and CLC-K2 mRNA expression in the kidney, and protein abundance of NKCC2 in kidney is positively regulated by Ang Ⅱ. These effects may contribute to enhanced renal Na+ and Cl- reabsorption in response to Ang Ⅱ. Chin Med J 2005; 118(23):1945-1951     

阿托伐他汀抑制血管紧张素Ⅱ诱导心房肌细胞肥大及对缝隙连接蛋白40的影响

目的观察阿托伐他汀对血管紧张素Ⅱ（AngⅡ）诱导的心房肌细胞肥大及缝隙连接蛋白40（Cx40）表达的影响。方法20只1周龄左右Wistar大鼠,用于体外心房肌细胞的分离培养与鉴定。设置正常对照组、AngⅡ（1μmol/L）组、AngⅡ＋二甲亚砜组和AngⅡ＋阿托伐他汀0.1、1.0、10μmol/L共6组。72h后利用氚标亮氨酸掺入法检测心房肌细胞蛋白合成速率,逆转录聚合酶链反应分别检测脑钠肽的前体（Nppb）、转化生长因子（TGF）-β1Cx40 mRNA的表达。结果与正常对照组相比,AngⅡ组氚标亮氨酸掺入量和Nppb mRNA表达呈显著性增加（P〈0.05）,同时TGF-β1mRNA高表达而Cx40mRNA低表达,阿托伐他汀逆转上述变化,10μmol/L组作用最强（P〈0.05）,而作为溶剂的二甲亚砜无明显作用。结论阿托伐他汀可能通过抑制Nppb mRNA的高表达来逆转AngⅡ诱导的心房肌细胞肥大,抑制TGF-β1RNA的高表达减轻心房纤维化,同时可能通过增强Cx40 mRNA的表达来逆转缝隙连接蛋白的重构,最终减低房颤发生率。